condition mean min max ZT0-3 5.7144375 5.274595 6.15428 ZT4-7 4.925364999999999 4.925364999999999 4.925364999999999 ZT8-11 4.38925 4.38925 4.38925 ZT12-15 0 0 0 ZT16-19 9.38947 9.38947 9.38947 ZT20-23 6.91503 6.91503 6.91503